Variable reactive coupling winding



R. S. PIPER Oct 1, 1929.

Filed July 31, 1926 2 Sheets-Sheet l Oct. 1, 1929. 5, mpg; 1,730,240

VARIABLE REACTIVE COUPLING WINDING Filed July 31, 1926 2 Sheets-Sheet 2 Patented Oct. 1, 1929 UNITED STATES RALPH S. PIPER, OF CHICAGO, ILLINOIS VARIABLE REACTIVE COUPLING WINDING Application filed July 31,

My invention relates to high frequency transformers and coupling coils, used especially in radio work but it is capable of a varied application in signal systems, registeringdevices, etc. I

More particularly stated the invention applies -to the windings and their relative dispositions with respect to each other when wound into coils, which permit a variable coupling characteristic to be introduced into zthe'action of said coils, air-type transformers and other inductive reactive devices.

As instances of the use of my invention such devices will be found to be especially serviceable either as oscillatory coils per se,

or as coupling coils between the several circuits useful in transmitting damped or undamped oscillatory currents, either to an antenna or its equivalents, or to the receiving'elements of aradio-frequency receiving set,-etc.

The present invention may be considered as presenting further improvements along the general lines laid down in my prior Patent 1,438,854, granted Dec. 12, 1922 and as stated generally above relates particularly to windings of certain shapes and their relations to each other to-give a variablecoupling characteristic, all as explained more in detail in connection with the accompanying drawings, which constitute part of this specification and in which:

Figure 1 is a perspective view showing a pair of coils in close coupled relation;

Figure 2 shows a similar pair of coils in open coupled relation;

Figures 3 and 4 show a modification of the invention useful especially in radio frequency work;

Figure 5 shows partly in cross sectional elevation a further modification especially adapted to regulate both the capacity coupling and the magnetic coupling of a pair of coils;

Figure 6 shows in plan view a pair of coils designed to exhibit a similar type of coupling to that shown in Fig. 5;

Figure 7 is a front elevation of the coils shown in Figs. 5 and 6 Referring especially to Figures 1 and 2,

1926. Serial No. 126,273.

two coils marked 1 and 2 are mounted enerally symmetrically around an axis or s aft 3, on which the inner coil 1 may be revolubly carried; however this coil 1 could be fixed and the same results obtained by providing for angular rotation of coil 2.

The inner coil 1 is of the same general shape as the inside coil described in my Patent 1,438,854, that is, its windings approximate a parallelogram in contour but other polygonal forms may be used without departing from my invention.

The outer or envelope coil 2 is so wound that, while symmetrical with respect to shaft 3, it presents a pair of salient portions 4 and 55 5, which embrace the opposed smaller end turns of winding 1, either in fairly close coupled relationship, as shown in Fig. 1, or in a pronounced open coupled relationship as shown in Fig. 2, depending on whether the inner coil 1 is in the relative angular osition with respect to coil 2 as shown in F 1g. 1, or in a position at right angles thereto, as shown in Fig. 2. It will be apparent that between the extreme positions indicated in these two Figures 1 and 2, an intermediate degree of coupling exists between the coils 1 and 2, for instance, when coil 1 is turned 45 degrees from the position shown in Fig. l, two of its corners will still be within the 30 salients 4 and 5 of the outer winding 2, and while the coupling as a whole between the two coils 1 and 2 will be more open than as shown in Fig. 1, it will be closer on the average than as shown in Fig. 2.

The sections of envelope 2, constituting the salients 4 and 5, as shown in Fig. 1, are substantially concentric with the portions of the inner winding 1 opposed thereto. From this relation it is apparent that throughout the salient area the spacing of the two windings will be uniform, thus giving a uniform air gap in all angular positions of adjustment, varying in area, up to the angle at which the circular section of winding 1 begins to leave the salient area.

Figs. 3 and 4 show the same general characteristics of winding which exist in Figs. 1 and 2, but the magnetic linkage betweenthe windings 1 and 2 has a constantly varying about any desired graduation of air gap be-' tion.

in transmitting station work and in receive ing sets. This smoothness in operation can be further enhanced by proportioning the relative extents of the windings to bring tween the two, with relative change in posi- Figure illustrates a form of the invention in which the outer, or envelope coil 2, is

again given the shape of an ellipse, marked 6. This outer coil is supported by a Bakelite ring 7 surrounding its middle section, the ring being fastened to a base plate 15. The base plate is shown as further provided with 'a air of end brackets 16 and 17 into which a akelite tube 18 is fixed. This tube is frictionally engaged by sleeves .30 on which the inner polygonal windings 1 are mounted. These sleeves are capable of a more or less tight engagement'with tube 18, but are nevertheless freely adjustable thereon, slidably and rotatively, so that they can be placed in any desired position with respect to the outer coil.

fected by means of push rods 19, which are' fixed tothe spider arms supporting the coils The placement of the coil 1 may be ef- 1. Each of the coils carries two end terminals 9, 10-11, 12-13, 14 to permit of insertion in various types of circuits.

Coils 1 are shown dotted in one position.

It will be seen that the assemblage of coils indicated in Fig. 5 gives a variable magnetic coupling and at the same time permits of a control of the capacity effects which always exists between conductors reacting on each other. When coils 1 21min their extreme end positions against the brackets 16 and 17 the capacity coupling between coils 1 and the outer coil 2 is very slight and yet a considerable magnetic coupling variation can be had in this position. 1

From the above explanations of the structures and results obtained by the several forms of my invention, it will be seen that each form of the invention retains the possibility of a most favorable automatic adj ustment of the average field distribution to effect circuit resonant reactions,-as explained in my prior patent, and gives the further possibility of a distinctly different set of irregular facets about which this self adjustment property can be exerted.

What I claim as my invention is 1. In an air core coupling transformer, a winding comprising turns of variablecontour radii, defining salient surfaces, a companion winding designed to bridge said surfaces to effect different degrees of magnetic coupling therewith, and means for placing these windings in relatively different positions with respect to each other, around an axis at right angles to the plane of said turns.

2. In a coupling transformer, a rotor winding and an enveloping winding surrounding said rotor winding in varying spacing separation and mounting means for said windings permitting of various degrees of approach between adjacent faces of said windings while retaining them in the same winding plane. 7

3. In a radio coupler an envelope coil having symmetrical convolutions arranged in parallel planes with portions of said convolutions having a like radius of curvature and other portions having a varying radius of curvature in combination with an inner coil whose turns are in planes parallel to the turns of the envelope coil, and co-axial therewith, the said inner coil presenting symmetrically placed peripheral sections of enlarged diameter with respect to other portions of the coil,- the said coils being relatively adjustable to each other angularly. 1

4. In a radio transformer a winding made up of symmetrically formed lobes and a cooperating winding approximating an oblate cylinder in shape, said windings being mounted to be relatively adjustable to each other in the same plane 'aroimd acommon axis. 1

5. In a radio frequency transformer a winding presenting opposed field faces and a co-operating winding also presenting opposed field faces, the turns of each winding being arranged in parallel planes and formed of a configuration designed to permit of said windings being placed in close coupled relation across their opposed faces, or in open coupled relation when angularly shifted from their close coupled position.

6. In a variable inductance transformer, primary and secondary windings having turns in parallel planes and presenting to eachother concentric surfaces and excentric surfaces within a given range of angular adjustment, in combination with mounting means for placing said concentric surfacesin opposition to each other with a constant air gap spacing between them in a plane at right angles to the winding axis and for varying the area of said air gap.

RALPH S. PIPER. 

